Effect of surface roughness on erosion wear of turboshaft engine compressor blades

When a turboshaft engine operates in a sand-laden environment, it is prone to erosive wear, which leads to the continuous evolution of surface roughness on compressor blades and consequently alters particle impact behaviour. However, existing studies have mainly focused on the erosion process of smooth surfaces, and there is still a lack of in-depth understanding of the influence of surface roughness on the erosive wear of multi-stage compressor blades. To address these issues, this paper theoretically derives the intrinsic relationship between blade surface roughness and wear rate. An erosion experimental setup for titanium alloy with adjustable impact angles is established to accurately characterize key parameters of the erosive wear model for titanium alloys with different surface roughness values. A dynamic model of blade erosive wear based on gas–solid two-phase flow is constructed, and computational fluid dynamics is employed to analyse the effects of sand particles on the distribution characteristics of erosive wear on compressor blades with varying surface roughness. The research reveals that in the erosion wear experiments conducted at impact angles ranging from 0 to 90°, titanium alloys with different surface roughness exhibited the highest wear rate at an impact angle of 30°. At this specific impact angle, the maximum erosion wear depth of the titanium alloy with Ra =6 µm increased by 88.9 % and 183.3 % compared to those with Ra =3 and Ra =0.1 µm, respectively. Roughness has the most significant impact on erosive wear of rotor blades, followed by stator blades, and the least on guide blades. As roughness increases, the maximum wear rate concentration on the blades rises, while the location of the erosion-concentrated area does not significantly shift with changes in roughness. The results can provide a basis for the erosion wear assessment of compressor blades at different service stages.